Micro - Antibiotics Flashcards
What class is vancomycin?
Glycopeptide
Cell wall synthesis blockers. Vanc is nephrotoxic
Teicoplanin is the other one - can cause neutropenia and leukopenia.
Which drugs block nucleic acid synthesis?
Trimethroprim - inhibits DHF reductase
First line for common UTI
Sulphonamide - inhibits DHOp
Combination - Co-Trimoxazole - used for PCP
Which drugs block DNA replication?
Quinolones - Ciprofloxacin - DNA gyrase (and topoisomerase IV) inhibitor
Anaerobes DNA inhibitor - Metronidazole and Nitrofurantoin
Which drugs block RNA synthesis?
RNA polymerase inhibitor - Rifampicin
Regarding protein synthesis inhibitors?
Which subunits
Aminoglycosides - Gentamicin, Amikacin - 30S
Macrolides - Erythromycin - 50S
Chloramphenicol - 50S - rarely used as can cause aplastic anaemia
Tetracyclines - 30S - also not used so much as cannot kill bacteria
23s component of 50S - Linezolid - can treat VRE
Gentamicin
Aminoglycosides - 30S
Erythromycin
Macrolide - 50S
Chloramphenicol
50S
Tetracycline
30S
Linezolid
23s component of 50S - treats VRE
Drug Resistance
Altered Target
Modify the target the drug is targetting
eg
MRSA modifies the target on its wall (PBP2a)
Cipro resistant modifies DNA gyrase so cannot be inhibited
Drug Resistance
Make enzymes
Beta lactamases made by lots of bacteria
ESBL especially powerful
Drug Resistance
Altered Drug Permeability
Cipro resistance - decreased influx of drug due to reduction in aquaporins
Drug Resistance
Additional Target
Co-trimoxazole resistance - Co-tri inhibis DHFR but resistant bacteria can make a different enzyme to do the same job, meaning there’s an ‘additional target’
